A Beginner’s Guide to Crypto Private and Public Keys

Beginner’s Guide / 16.12.2018

As a beginner in the crypto space, you may be wondering what public keys and private keys are and why you really need them.  Private and public keys are vital in cryptocurrency and blockchain to safeguard transactions. If you’re seeking to enter the crypto space, it’s essential to understand private and public keys. Here’s an in-depth look at each of them. 

Understanding Cryptography: The Basic of Private and Public Key

Private and public keys are elements of cryptography. Cryptography, also referred to as cryptology, is the study and practice of encrypting information and communications via codes so that only the intended audience can read and decrypt the information. Cryptography is an essential component of blockchain technology. Blockchain employs cryptography for several purposes, notably: 

  • Protecting users’ identity– Cryptography on blockchain networks enables individuals to safeguard their personal identities and data when conducting transactions across the network. Cryptography gives each person a means of securing their identities. 
  • Ensure transactions are safely done– Cryptography ensures that transactions are conducted safely. Through the use of cryptography, cryptocurrency transactions are secure, viable, and valuable. 
  • Secure blocks– Once confirmed, transactions on a blockchain network turn into blocks added onto other blocks to form a blockchain. Blockchain deploys blockchain technology to secure the network blocks so that any party cannot alter them without consensus. 

There are three primary forms of cryptography in the blockchain that can be used to perform cryptographic algorithms. These are asymmetric key cryptography, symmetric-key cryptography, and hash functions

Symmetric-Key Cryptography– Symmetric-key cryptography employs a single key to achieving cryptographic algorithms. This Key is shared among users meaning that it can be used for both the encryption and the decryption process. Symmetric-key is also referred to as secret-key cryptography and can be exchanged between the sender and the receiver. In common terms, the symmetric-key is the public Key. 

Asymmetric-Key Cryptography– Asymmetric-key cryptography achieves cryptographic algorithms via a pair of keys, i.e., an encryption key (Public Key) and decryption (private Key). Both the encryption and decryption keys are generated using the algorithm.

Hash Functions– Hash function encryption doesn’t leverage keys. Instead, it uses a cipher to generate a hash value of a fixed length from the text. The hash function is referred to as mnemonic phrase, seed key, and seed in common terms. Blockchains generally use the SHA-256 hashing algorithms as their hash function.   

What is a Private Key?

A private key can be defined as an asymmetrical form of cryptography that allows users to access their cryptocurrencies in a wallet. Private keys are an integral part of a blockchain and function to prevent unauthorized access to funds. Every blockchain user has a public and private address used in sending and receiving tokens. Private keys are used to safeguard the wallet and take different forms, usually represented as alphanumeric characters. 

Private keys are stored in a crypto wallet. When a user initiates a transaction, the wallet creates a unique digital software by processing the private key transaction. This ensures that the wallet is secure since the only means of generating a valid signature for any transaction is through the use of a private key. The signature is unique for every transaction and functions to authenticate that a transaction has originated for a particular user. Signatures also ensure that the private key cannot be altered once broadcasted as it changes with every alteration. 

If you lose or forget your private key, you can no longer access your crypto wallet. However, you can use your mnemonic phrase or passphrase to get back your wallet once you’ve lost or forgotten your private keys. Therefore, you must store your private Key, seed key, and passphrase in a safe and secure location where nobody can access them. 

What is Public Key?

A public Key is a form of symmetric key cryptography that allows crypto users to receive cryptocurrencies to their crypto wallets. The public key is generated from the private key via a complicated mathematical algorithm, i.e., The Discrete Log Problem. It’s therefore impossible to reverse the public key to get the private keys. But it’s easy to create the public key given the private key.

Public key cryptography is vital in the crypto space to offer security for transactions on the blockchain. Cryptocurrencies are decentralized, meaning that no third party is eligible for offering security. Unlike private keys, public keys can be shared with other users on the network to send or receive cryptos.     

Private Key vs. Public Key: How Do They Work

In the crypto space, a private and public key combines to create a digital signature that can be used to grant access to a piece of transaction or information. If an individual wants to send information or conduct a transaction on the blockchain, they need to use their public and private keys together. This means that both the private and public key function in unison to create a digital signature used to provide transaction security. 

Private keys are extraordinarily long and random characters (letters and numbers), while public keys are (x,y) points on an Elliptic Curve generated using the private key as a scalar. Understanding how they function takes a public key as a mailbox and the private key as the key to the box. The main office can insert letters and other packages to the mailbox through the back opening. However, a unique key is required to retrieve the contents in the mailbox. 

Take this as an example: 

Kevin and Mike are friends leaving apart. Kevin wants to send Mike a message. Therefore, Kevin is the message sender, Mike, the message recipient, and their own public and private keys. When Kevin sends Mike a message in a blockchain network, Kevin’s message is encrypted with Mike’s Public Key. This means that only Mike’s private key can decrypt the information. 

A digital certificate or signature is required to verify that Kevin is the original sender of the message. To verify this, Mike uses Kevin’s Public Key to decrypt the message, which Kevin initially encrypted using his private Key when sending the message. Once decrypted and readable, it means that Kevin is the valid sender of the message. Therefore, the digital signature is authenticated with a certification authority (CA).    

Final Words

Both Private and public keys are vital components in the crypto sector to ensure users and transactions’ security. When using cryptocurrencies, users are given both a public address and private key to send and receive coins. Combining an individual’s public and private keys creates a digital signature that functions to safeguard transactions. Always remember that losing or forgetting your private keys is equal to losing your crypto assets. Therefore, make sure to store your private keys most securely and safely possible. Also, never disclose your private keys to anyone, at least if you don’t trust them. 

Adam is an outgoing young lad who likes adventures and discovering new things. Despite his boring life, he loves writing about cryptocurrencies and exploring what blockchain technology can do for the coming digital world where all adventures will be virtual.